ML19263D833
| ML19263D833 | |
| Person / Time | |
|---|---|
| Issue date: | 12/27/1978 |
| From: | James Shea NRC OFFICE OF INTERNATIONAL PROGRAMS (OIP) |
| To: | |
| References | |
| AB60-2-376, SECY-78-685, NUDOCS 7904130311 | |
| Download: ML19263D833 (5) | |
Text
.
December 27, 1973 a
NS SECY-78-685 NUCLEAR REGULATORY cOMMissiCN INFORMATION REPORT Fo,r :
The Ccmissioners Frem:
James R. Shea, Director Office of International Programs Executive Director for Operations' j [! - ~
Thru:
'x W
Subject:
GE!4ERAL ATOMIC DE'/ELOPME:li 0F LEU FUEL FOR RESEARCH REACTORS Purcose:
To inform the Comission of the staff's further examina-tion of the questien of using LEU in connection with future research reactor fuel license applications (as requested by Ccmissioner Gilinsky in George Eysymontt's November 7 memo to James Shea).
Discussion:
In a recent transmittal of several reports to Ccmissioner Gilinsky, General Atomic claims to have developed LEU TRIGA fuel which could be used commercially in TRIGA reactors and also as a substitute in certain of the reacto:
using plate-type fuel.
Before addressing the specific claims made by General Atomic, the following observations on research reactors and fuel types are presented to put this in perspective.
With a few minor exceptions, there are basically two types of fuels for research and test reactors new in use:
(a) red-type uranium-rirconium hydride fuels utilized in TRIGA reactors, wnich are manufactured by General Atcmic and are known as TRIGA fuels and (b) plate-type, aluminum-clad fuels, which are used in vircually all other types of reactors, such as Materials Test Reactors (MTRs).
The pcwer levels of the TRIGA reactors run frcm ten kilcwatts to a maximum of 14 megawatts.
Of the total number of research and test reactors in operation in the non-Communi?
countries, about 20% are of the TRIGA type.
(TRIGA-tyce fuel elements may also be used ~ interchangeably with comparable plate-type fuel elements in scme reactors.)
Contact:
H. 3. Schechter, IP (292-8155)
G. G. Colinger, IP
(;92-7866) 7 9 0413 0 3fl
. The reactors using plate-type fuel normally range in power level from one megawatt to a maximum of 100 megawatts. Well over 90% of all HEU utilized for research reactors in the non-Ccmmunist countries is in reactors with plate-type fuel. Of these, many are operated at such icw power levels and utilization rates that their fuel may last for two to ten years or more. However, scme 15 to 20 of these reactors, generally located in several highly industrialized states, operate at high specific power and utiliza-tion levels and account for all but a small portion of U.S.-origin HEU inventories abr0ad.
TRIGA (rod-type) fuel is fabricated only in the United States. At present it is made in enrichments of 93.5%, 70%, and 20% U-235, and with a uranium density of 8.5 and 12 weight percent, depending on the reactor pcwer level and fuel cycle economics.
There currently is no commercial fabricator of plate-type fuel in this country.
As regards the claims made by General Atomic, they are essentially correct up to a point.
For the lower power level MTRs (less than about 3MW), conversion to medium density (approximately 20% uranium by weight) LEU TRIGA fuel can be made without tco much difficulty.
On the other hand, DOE personnel and Dick Lewis (formerly of Argonne and now at State) estimate that the higher power MTRs (above 3 MW) wculd require major and costly modifications (i.e., of the crder of several hundred thousand dollars) before they could accept the high density (about 45 weight %) LEU TRIGA fuel that would be needed to maintain their operating cerformance.
GA disagrees with this view, arguing that unless operators embark oa a major program to upgrade the overall reactor, difficulties would not be major and costs (excluding purchase cost of the fuel) should not exceed 375-$100 K.
Furthermore, as noted above, there are several reactor types that cannot use TRIGA fuel, e.g. the liquid fuel L-77 reactors (at U.C. Santa Barbara, Brigham Young University, Cologne and Julich, FRG, and Rockwell International).
The assessment of the likely
. difficulty in converting the higher pcwer MTR reactors is particularly imcortant in the context of U.S. fuel exports because, as indicated earlier, the largest amount of exported HEU fuel is destined for these higher pcwer reactors.
In checking with General Atomic, the staff determined that GA's statement that the new high density fuel is "available" means that they have the manufacturing ability and could deliver a core of high density LEU fuel within 6-9 months after receipt of an order.
None of this LEU fuel is actually available at this moment.
GA has started talks with Thailand and Brazil aimed at marketing lcwer enrichment fuel, but so far has not received any firm purchase orders from these countries.
( Thailand's reactor is in the 1-2 MW range and Brazil's reactor is at a 10 MW level.
Both use plate-type fuel.)
Beyond this, there is also the question of long-range reliability of the high density LEU fuel and its safety.
GA staff members maintain that, on the basis of developmental work performed so far on this fuel, they are fairly confident that the results of future longer-term tests will not differ substantially frca the favorable results attained on the basis cf the more limited tests conducted to date. Mcwever, this contenticn is based only on projections of limited tests and is not backed up by solid experimental evidence. So far the NRC has only authorized use of this kind of fuel in General Atomic's Mark F reactor (in San Diego) for the purpose of conducting tests under stringent surveillance.
The surveillance requirements would probably be relaxed folicwing completion of the tests (now scheduled for mid to late 1980) if the results are satisfactory.
Additionally, NRC will probably restrict the operation of any TRIGA reactor converted to LEU to less than full burnup until full burnup tests on both high and medium density LEU fuels are ccmpleted at ORNL.
These tests are expected to ccmmence around September 1979 and should last frcm six months to one year.
Although, as indicatc; earlier, many 1cw pcwer olate-type reactors could be converted to the use of LEU TRIGA fuel, each conversion wculd have to be evaluated by the users
_4_
and their regulatory bodies to ensure that experimental 3 cperational and safety requirements will be met after conversion.
DOE has centracted with D. Lanning (MIT) and K. Almenas (U. Md.) for a stucy of the viability of using LEU TRIGA fuel as an alternative fuel for non-TRIGA reactors.
Their report shculd be available in early 1979.
It is cenerally accepted that LEU TRIGA fuel cannot meet all research reactor needs, and there-fore DOE is actively exploring other alternatives in its enrichment reducticn program.
For example, COE is funding development of LEU plate-type fuel by both Texas Instruments and Atomics International.
AI's MTR type high density fuel has been scheduled for full core demonstration testing at the University of Michigan around July 1979.
Pending satisfactory completion of all the conversion activities and safety reviews noted above (estimated by COE to take arcund 3 years--Ref.: SECY-78-458 of August 21) and clarificaticn of US domestic licensing reonirements, State, DOE, and Argonne staff believe that most foreign operators of the higher power research reacters (both TRIGAs and MTRs) will be reluctant to switch to LEU TRIGA fuel even if, as a result of GA's early start in this area, full burnup tests of this fuel might conceivably be completed several months ahead of the plate-type fuels. On the other hand, GA intends to begin supplying only their icwer density LEU TRIGA fuel to operators of lower power research reactors as soon as their present HEU cores are burned up.
It appears that the majority of foreign reactor operators have adopted a wait-and-see stance regarding reactor conversion, and the rate of future acceptance of LEU fuel by foreign users is difficult to predict at this point.
GA personnel have informally indicated they agree with this assessment. Hcwever, GA believes that Brazil may well agree to utilize the new LEU fuel within 6-9 months.
COE and Argonne personnel believe that it wcuid be inadvisable for the U.S. (including the NRC) to cress foreign users of higher pcwer reactors too hard to make an early commitment to LEU TRIGA fuel. The concern is that any U.S. pressure for early adoption of TRIGA fuel
. would be viewed as an attempt to secure the foreign fuel market for General Atemic, thereby undermining the close cooperation and succort of CERCA and NUKEM, the two principal foreign plate fuel fabricators, for the COE conversicn program.
In addition to the US efforts, the French have plans to make their new 7% enriched Caramel fuel, which was developed for the 70 MW French Osiris reactor, ccmmercially available in 1980.
Cccedination:
0 ELD has no legal objection.
NRR/CCR staff has provided technical inputs on the status of LEU TRIGA fuel activities. This information was also confirmed by informal discussions with perscnnel of General Atomic and the Department of Energy.
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James R. Shea, Director Office of International Programs DISTRIBUTION Commissioners Commission Staff Offices Exec Dir for Operations ACRS Secretariat